dimensions

...are even smaller, such as
Mycoplasma pneumoniae, which is one of the smallest bacteria, ranging from about 0.1 to 0.25 μm in width and roughly 1 to 1.5 μm in length; the rod-shaped
Bordetella pertussis, which is the causative agent of whooping cough, ranging from 0.2 to 0.5 μm in diameter and 0.5 to 1 μm in length; and the corkscrew-shaped
Treponema pallidum,...

discovery by Bordet

...agents in the blood, including those that cause typhoid, tuberculosis, and, most notably, syphilis (the Wassermann test). After discovering (with Gengou in 1906) the bacterium, now known as
Bordetella pertussis, that is responsible for whooping cough, Bordet became professor of bacteriology at the Free University of Brussels (1907–35).